Flat battery

[gladders]

My battery seems to lose charge when it is left for any time not on charge. Had a run up to Squires cafe last weekend approx 50 miles and parked up for about 4 hours while we went round the autojumble, when I came to start the bike it wouldn't turn over on the starter and I had to kickstart it.

What could cause this and how do I find the problem?
Grant

[yeadon_m]

Grant, two most-likely possibilities I think:
1 - something is drawing current even when ign switch is off. You could test by placing an ammeter in series with the fuse (break that link and attach one end to each of the AVO meter terminals with swicth off - should read zero amps).
2 - battery is a bit knackered! test by fully charging, then leaving off charge for a couple of hours, and then attaching a volt meter in parallel across batt terminals and put lights on. If voltage rapidly falls to way below 12v, it is not capable of holding much of a charge.

The fix for 1 obviously is to find the source of drain by disconnecting block connectors until current goes to zero. Possibly rect/reg. For 2, buy a new battery :-)

My B battery is like this. I will buy a new one in spring.
Hope helpful, cheers!
Mike

[gladders]

Hi Mike,

I don't have an ammeter but have fully charged battery and checked voltage at 12.98v connected it up and left it for 7 days reading was 12.86v, switched on ignition and high beam and reading dropped to 11.99v and stayed steady, switched lights and ignition off and reading rose to 12.21v.

With battery fully charged when I press the starter switch the motor bogs down for a couple of turns sounding like a flat battery then starts to spin freely and fires up, is there anything on the starter circuit that could cause these symptoms

When running at 2500 revs the battery is charging at 14 volts,

Thanks
Grant

[BAZ]

Sounds like you have a faulty starter motor to me. Use the kick-start and see how you get on

[gladders]

Hi Baz, she fires up really easy every time on the kick start, is there a way to test the starter or do I have to buy a new one?
Grant

[BAZ]

If the starter is failing the earth lead and the live feed to the motor get very hot. It is a bit of a pain changing the motor but substitution is the best test. You can usually repair thay motors they are very well made.

[astrax]

May be worth checking the brushes in the starter motor, with a bit of luck may be something simple like that.
Also can try giving the copper strips on the starter motor a clean up with fine wet or dry ( 400 - 600 grit should do ) and clear out any muck between the copper strips.

[gladders]

Thanks chaps,

I will remove and strip the starter as suggested, where is the coolant drain plug as the Haynes explanation is a bit confusing a picture would be greatly appreciated.

[BAZ]

Here

[gladders]

Thanks Baz